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<head><meta charset="utf-8"><title>tracing · t-compiler/rust-analyzer · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/index.html">t-compiler/rust-analyzer</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/topic/tracing.html">tracing</a></h3>

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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/185405-t-compiler/rust-analyzer/topic/tracing/near/204955362" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> matklad <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/topic/tracing.html#204955362">(Jul 24 2020 at 19:13)</a>:</h4>
<p>Seems like the time has come to replace our home-grown profiling infra with tracing: <a href="https://github.com/rust-lang/rust/pull/74726">https://github.com/rust-lang/rust/pull/74726</a></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/185405-t-compiler/rust-analyzer/topic/tracing/near/205032911" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Christopher Durham <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/topic/tracing.html#205032911">(Jul 26 2020 at 02:57)</a>:</h4>
<p><span aria-label="eyes" class="emoji emoji-1f440" role="img" title="eyes">:eyes:</span> but also ouch on that perf report <span aria-label="sweat" class="emoji emoji-1f613" role="img" title="sweat">:sweat:</span></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/185405-t-compiler/rust-analyzer/topic/tracing/near/205059567" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> David Barsky <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/topic/tracing.html#205059567">(Jul 26 2020 at 17:10)</a>:</h4>
<p>oh goodness, that's one hell of a perf report</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/185405-t-compiler/rust-analyzer/topic/tracing/near/205060384" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jonas Schievink  [he/him] <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/topic/tracing.html#205060384">(Jul 26 2020 at 17:34)</a>:</h4>
<p>is the compile-time max_log_level thingy not working?</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/185405-t-compiler/rust-analyzer/topic/tracing/near/205060665" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> David Barsky <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/topic/tracing.html#205060665">(Jul 26 2020 at 17:43)</a>:</h4>
<p>I think this might be the issue: <a href="https://github.com/rust-lang/rust/pull/74726#discussion_r460553066">https://github.com/rust-lang/rust/pull/74726#discussion_r460553066</a></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/185405-t-compiler/rust-analyzer/topic/tracing/near/205060666" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> David Barsky <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/topic/tracing.html#205060666">(Jul 26 2020 at 17:43)</a>:</h4>
<p>I was able to reproduce that on my computer</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/185405-t-compiler/rust-analyzer/topic/tracing/near/205060705" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> David Barsky <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/topic/tracing.html#205060705">(Jul 26 2020 at 17:44)</a>:</h4>
<p>(no playground link, unfortunately. tracing's not in there yet)</p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/185405-t-compiler/rust-analyzer/topic/tracing/near/205061956" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> David Barsky <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/topic/tracing.html#205061956">(Jul 26 2020 at 18:22)</a>:</h4>
<p>Eliza commented with more details: <a href="https://github.com/rust-lang/rust/pull/74726#discussion_r460557136">https://github.com/rust-lang/rust/pull/74726#discussion_r460557136</a></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/185405-t-compiler/rust-analyzer/topic/tracing/near/205141960" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> David Barsky <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/topic/tracing.html#205141960">(Jul 27 2020 at 16:58)</a>:</h4>
<p>Another update: after resolving the issues rustc encountered, the perf results indicated that tracing's within 10% of <code>log</code> when enabled (day-to-day rustc users won't see this). this regression occurs due to the initial callsite registration relatively slow (a few dozen milliseconds), but since tracing was highly optimized around long-lived network applications, this initial registration was almost completely amortized and invisible to most of <code>tracing</code>'s users. Eliza gave some additional details: <a href="https://github.com/rust-lang/rust/pull/74726#issuecomment-664482501">https://github.com/rust-lang/rust/pull/74726#issuecomment-664482501</a></p>



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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/185405-t-compiler/rust-analyzer/topic/tracing/near/205141986" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> David Barsky <a href="https://rust-lang.github.io/zulip_archive/stream/185405-t-compiler/rust-analyzer/topic/tracing.html#205141986">(Jul 27 2020 at 16:58)</a>:</h4>
<p>there should be a fix for this Soon, perhaps in the next day or so.</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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